improved docs and changelog for #8903

framework/db/pgsql/QueryBuilder.php

@@ -18,13 +18,24 @@ use yii\base\InvalidParamException;
 class QueryBuilder extends \yii\db\QueryBuilder
 {
     /**
-     * You can use any of these indexes for the postgresql 8.2+ version
-     * @see http://www.postgresql.org/docs/8.2/static/sql-createindex.html
+     * Defines a UNIQUE index for [[createIndex()]].
      */
     const INDEX_UNIQUE = 'unique';
+    /**
+     * Defines a B-tree index for [[createIndex()]].
+     */
     const INDEX_B_TREE = 'btree';
+    /**
+     * Defines a hash index for [[createIndex()]].
+     */
     const INDEX_HASH = 'hash';
+    /**
+     * Defines a GiST index for [[createIndex()]].
+     */
     const INDEX_GIST = 'gist';
+    /**
+     * Defines a GIN index for [[createIndex()]].
+     */
     const INDEX_GIN = 'gin';
 
     /**
@@ -81,8 +92,11 @@ class QueryBuilder extends \yii\db\QueryBuilder
      * @param string|array $columns the column(s) that should be included in the index. If there are multiple columns,
      * separate them with commas or use an array to represent them. Each column name will be properly quoted
      * by the method, unless a parenthesis is found in the name.
-     * @param boolean|string $unique whether to add UNIQUE constraint or if is $unique string create some of index.
+     * @param boolean|string $unique whether to make this a UNIQUE index constraint. You can pass `true` or [[INDEX_UNIQUE]] to create
+     * a unique index, `false` to make a non-unique index using the default index type, or one of the following constants to specify
+     * the index method to use: [[INDEX_B_TREE]], [[INDEX_HASH]], [[INDEX_GIST]], [[INDEX_GIN]].
      * @return string the SQL statement for creating a new index.
+     * @see http://www.postgresql.org/docs/8.2/static/sql-createindex.html
      */
     public function createIndex($name, $table, $columns, $unique = false)
     {